Fastener and method of making same

ABSTRACT

A fastener has a body with an attachment surface and a holding surface. A large number of tiny hairs protrude from the attachment surface. A hook, post, ring or other structure extends from the holding surface to permit an object to be hung from or attached to the fastener. The attachment surface can be formed by depositing or growing the hairs on a substrate or by using a mold to form the hairs.

FIELD OF INVENTION

The invention relates to fasteners which are applied to a surface to hold an object on that surface and methods of making those fasteners.

BACKGROUND OF THE INVENTION

One type of fastener that is commonly used to hold objects on a smooth surface is a suction cup. Suction cups have a flexible concave body and a neck extending from the body. When the concave surface is pressed against a smooth surface air is expelled from the region between the concave surface of the suction cup and the smooth surface against which the suction cup is pressed. After the pressing force is removed, the concave body seeks to return to its original shape which forms a vacuum between the suction cup and the smooth surface. The vacuum holds the cup on the smooth surface. Objects may then be hung from the neck of the suction cup. One advantage that suction cups have over nails, screws and adhesives is that they do not mar the surface on which they are attached. A disadvantage of using a suction cup as a fastener for holding objects is that suction cups can only be used on flat, smooth surfaces. Any irregularity or curvature in the surface may cause the suction cup to release from the surface immediately or after a short period of time.

Vinyl cut-outs have been used to decorate mirrors, windows and other smooth surfaces. When pressed against such a surface to remove air from between abutting surfaces, the cut-outs will remain on the mirror, window or other smooth surface for many weeks. These vinyl cut-outs may also be applied to smooth curved surfaces. However, the forces that keep the vinyl cut-out from falling are not strong enough to permit objects to be hung from the cut-out.

Many have observed geckos and insects climb and hang on vertical surfaces. Recently, scientists have discovered that the secret behind many such extraordinary climbing skills lies with millions of tiny keratin hairs, called setae, on the surface of each foot. An intermolecular phenomenon known as Van der Waals force is exerted by each hair. The combined effect of the millions of hairs collectively produce a powerful adhesive effect. Researchers at Carnegie Mellon University created a material made of millions of artificial hairs on a flexible substrate. Each synthetic hair is made of a material called kapton and measures 2.0 microns in height and 0.2 microns in diameter. The product was made using a mold created by a lithographic process. A piece of this material, which was one centimeter square and having about 100 million artificial hairs, was able to support a weight of one kilogram. Yet, scientists were concerned that the artificial hairs they had produced were not durable enough to be reapplied several times and the method used to fabricate the product would not lend itself to mass production of the product.

Consequently, there is a need for a process and material that together can produce a fastener that could be attached to and grip a surface in the same manner as the gecko. The method should be able to mass produce the product. Additionally, the product should have a hook or other structure that allows objects to be hung from or attached to the fastener.

SUMMARY OF THE INVENTION

I provide a fastener having a body with an attachment surface and a holding surface. A large number of tiny hair-like structures, hereinafter called hairs, protrude from the attachment surface. A hook, post, ring or other structure extends from the holding surface to permit an object to be hung from or attached to the fastener. The body can be a resin, preferably vinyl or silicon.

In a first present preferred process the hairs are formed on the attachment surface by drilling holes or tracks in the surface with one or more laser beams. The laser can rapidly create the tracks and holes that separate the hairs.

In a second present preferred process the hairs are grown on the attachment surface. This can be done using a particle deposition process such as vapor deposition.

In a third present preferred process the hairs are formed by a mold placed over the base material such as vinyl. The mold has hundreds of closely spaced, very small holes. A vacuum is applied to the top of the mold, drawing some base material into the holes and thereby forming the hairs. Then the vacuum is removed and the base material with hairs is separated from the mold. This ejection may be helped by air pressure or by curling the molded part away from the mold.

In another present preferred process the skin of an animal having closely spaced hair is selected. The hairy side is shaved to provide very short hairs on the skin. A hook, post or other structure is attached to the opposite side of the skin.

Other objects and advantages of the present fastener and methods of making same will become apparent from certain present preferred embodiments shown in the drawings.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a front perspective view of a present preferred embodiment of my fastener.

FIG. 2 is a rear perspective view of the fastener shown in FIG. 1.

FIG. 3 is a greatly magnified view of the portion of the fastener within circle 3 in FIG. 2.

FIG. 4 is a sectional view taken along the line IV-IV of FIG. 3.

FIG. 5 is a perspective view of a portion of a mold on a portion of base material which can be used in a present preferred process to make the fastener shown in FIGS. 1 through 4.

DESCRIPTIONS OF THE PREFERRED EMBODIMENTS

A first present preferred fastener 1, shown in FIGS. 1 through 4, has a flexible body 2 having a holding surface 4 from which objects can be held, or to which objects may be attached, and an attachment surface 6 which is pressed against an object or surface on which the fastener will be placed.

The holding surface 4 has a holding member 5 which is configured to receive an object. The holding member 5 may be configured as a hook, as illustrated in FIG. 1, or a post, ring or other shape which can receive an object. Multiple hooks, rings or posts could be provided. The holding member 5 may be integral with the body 2 or attached to the body after the body is formed. Preferably, the body is a material like vinyl, silicon or kapton. The attachment surface has many closely spaced hairs 8. A one centimeter square section of the fastener may have as many as 100 million hairs, each about 2.0 microns in height and 0.2 microns in diameter. When the attachment surface is pressed against an object the hairs and body may bend or flex to assume the shape of that portion of the object covered by the fastener. Van der Waals forces exerted by each of the hairs produce a powerful adhesive effect attaching the fastener to the object. Then another object may be attached to the holding member 5. The fastener is removed from the object by peeling the flexible body 2 from the object.

The hairs 8 on the attachment surface can be crafted in several ways. In one method the hairs are grown in place using particle deposition or crystal growing techniques which are well-known in the art. In a second embodiment the body 2 is an animal skin in which the hairs have been shaved leaving only a small part of the original hair extending from the surface of the skin. However, animal skins in which the hairs are not closely spaced may not provide a strong adhesive effect. Therefore, skins having closely spaced hairs, such as mink or chinchilla, should be used.

Other ways to create the hair-like structures on the attachment side of the fastener can be understood with reference to FIG. 5. A mold 10 is provided with a large number of small diameter, closely spaced holes 18. The holes may be drilled or cut by laser. The mold is placed on a material 11, such as vinyl, which will comprise the body of the fastener. Then a vacuum is drawn on the top of the mold. The vacuum draws or extrudes small amounts of the vinyl, silicon or other material 11 into the holes 18. When the vacuum has been removed small hairs will extend from the substrate material 11 into the holes. Then the substrate with hairs is ejected from the mold, either mechanically, magnetically or hydraulically.

For certain substrates it may be possible to form the hairs by pressing the mold 10 against the body. In this process the mold could be the surface of a roller such as a calendar roll.

Although the hairs in the embodiment shown in FIGS. 3 and 4 are illustrated as solid structures, they could be tubular. Such nanotubes may have a flat or curved top surface.

The attachment surface may be concave rather than flat. If the fastener is intended for use on a particular object, the body may have a shape that is complementary to the portion of the object on which the fastener will be placed. The body of the fastener preferably, but not necessarily, is flexible.

Magnetic particles may also be used to form the hairs. Milled to the proper size, many particles may be made to stack on top of each other, forming the hair-like structures. They may be solidified by heat, gas, partial dissolving, radiation, or pressure.

Although I have shown and described certain present preferred embodiments of my fastener and methods for making same, it is to be distinctly understood that the invention is not limited thereto, but may be variously embodied within the scope of the following claims. 

1. A fastener comprised of: a body having an attachment surface and a holding surface; a plurality of hairs extending from the attachment surface, the hairs sized and spaced so that when the attachment surface is pressed against a second surface Van der Waals forces between the attachment surface and the smooth surface will hold the body and a weight held by the body on the second surface; and a holding member extending from the holding surface, the holding member configured to hold a structure having a weight not greater than the weight which can be held by the body when that body is pressed against the second surface.
 2. The fastener of claim 1 wherein the holding member is a hook, post or a ring.
 3. The fastener of claim 1 wherein the body is flexible.
 4. The fastener of claim 1 wherein the body is vinyl or silicon.
 5. The fastener of claim 1 wherein the hairs are nanotubes.
 6. The fastener of claim 1 wherein the attachment surface is concave.
 7. A method of making a fastener of the type in which a flexible body has an attachment surface and a holding surface comprising: providing a body having a first surface and a second surface; providing a plurality of hairs on the first surface to create the attachment surface; and providing at least one holding member on the second surface to create the holding surface.
 8. The method of claim 7 wherein the holding member is a hook, a post or a ring.
 9. The method of claim 7 wherein the flexible body is vinyl or silicon.
 10. The method of claim 7 wherein the hairs are nanotubes.
 11. The method of claim 7 wherein the plurality of hairs are provided by drilling or etching the first surface.
 12. The method of claim 7 wherein the plurality of hairs are provided by being grown on the first surface.
 13. The method of claim 7 wherein the plurality of hairs are provided by being extruded from the first surface.
 14. The method of claim 7 wherein the plurality of hairs are provided by vapor deposition.
 15. The method of claim 1 wherein the holding member is provided by forming the second surface to create at least one hook, post or ring. 